This is the sub-section of the Digital Research Library containing all material on the topic of out-of-hospital sudden cardiac arrest (OHCA), resuscitation, the cardiac chain of survival, CPR, chest compressions, ventilation and rescue breathing, defibrillation, and intra-arrest drugs.
Cardiac arrest care has been at the heart of prehospital medicine since its inception, and much of modern EMS is dedicated to providing optimal care for cases of out-of-hospital SCA (sudden cardiac arrest). Since the first introduction of CPR and defibrillation in the 1960s, a large body of research has investigated best practices for maximizing survival in this high-mortality cohort.
Every five years, the International Liaison Committee on Resuscitation (ILCOR) reviews the existing evidence and issues revised guidelines for resuscitation, which are adopted internationally (with small customizations) as standard of care for SCA. In the US, this is via the American Heart Association (AHA), whose recommendations are published in the Circulation journal; the most recent was released in 2010. These are heavily cited and well-supported documents, and their reference list can be easily mined for the relevant studies on various subjects.
When reviewing the literature, it is important to consider both the baseline details of the cohort studied, and the endpoints being evaluated. Vastly different outcomes may be seen between populations depending on their proportion of witnessed arrests, frequency of bystander CPR, time-to-EMS-arrival, and other baseline variables; research from Singapore may, therefore, lack external validity in Seattle. Conversely, when considering outcomes, there is a cascading series of nested, yet distinct endpoints: how many patients achieved a return of spontaneous circulation (ROSC)? How many of those survived to hospital admission? How many of those survived to hospital discharge? And how many of those were discharged neurologically intact? Only survival to neurologically-intact discharge is generally accepted as “true” survival (dying in the ICU is not better than dying on scene); however, many interventions may improve short-term outcome (such as ROSC) without improving this ultimate endpoint, and the value of such measures is debatable.
Much of the existing research focuses in several areas:
Pharmacology: Drugs have been given to SCA patients during resuscitation for many years. Some have been shown ineffective or harmful and are no longer routinely recommend (bretylium, isoproterenol, bicarbonate, atropine, etc). Others are still believed to be potentially valuable (epinephrine, amiodarone). In general, the support for drugs is based on physiological reasoning and their success in improving surrogate endpoints — such as coronary perfusion or rate of ROSC (return of spontaneous circulation) in laboratory trials (eg. swine models). Although some drugs have been shown to increase the chance of ROSC, no drug has ever consistently demonstrated an improved chance of survival to hospital discharge with good neurological status, and some drugs may improve ROSC but actually decrease survival to discharge. Randomized controlled trials are rare, (although see Olasveengen  and Jacobs for epinephrine, and Kudenchuk for amiodarone). AHA guidelines now deemphasize pharmacological interventions such as epinephrine due to this absence of evidence for true survival, but do not (yet) recommend against their use altogether. Promising novel drugs such as intra-arrest nitrates and female sex hormones are currently being studied.
Chest compressions: External chest compressions remain a core component of resuscitation. A growing body of evidence has demonstrated the positive effect of chest compressions on survival, more recently emphasizing the importance of their quality, namely compressions that: are initiated as early as possible after collapse; are continued without any interruption; are deep, fast, and recoil fully; and are not compromised for other interventions except defibrillation. A variation known as cardiocerebral resuscitation (CCR), or “hands only CPR” has been shown to improve survival over CPR-with-ventilation; this is now recommended for lay providers (due to ease of training, effectiveness, and bystander reluctance to administer mouth-to-mouth breaths), and many EMS services are increasingly adopting resuscitation protocols that embrace these principles.
Ventilation: Insufflation of oxygen-rich air into the patient’s lungs is a traditional component of CPR. In recent years the importance of this has been deemphasized, due to the low oxygen demands of a poorly-perfusing patient, high levels of reserve oxygen after sudden collapse, passive air movement provided by chest compressions, and the deleterious effect on circulation of frequent pauses for positive-pressure ventilation. Most high-performance EMS systems have adopted the practice of providing ventilations only after compressions and defibrillation have been addressed, except when arrest is presumed secondary to hypoxic causes. Otherwise, ventilation (by BVM or particularly intubation) has generally been shown to have no effect, or to have a deleterious effect, upon survival.
Defibrillation: Electrical cardioversion remains the definitive treatment for ventricular fibrillation or pulseless ventricular tachycardia. Research has generally shown the effect of different pad/paddle positions, electrical waveforms or amperages, and other details to be minimal; however, early defibrillation is unquestionably key to survival. Automated external defibrillators (AEDs) have been shown to be safe and generally as effective as manual monitor/defibrillators, and are usable by willing lay providers when available in public areas. Specialized techniques such as “double sequential external defibrillation” (DSED) for refractory v-fib are currently being studied.
Adjunctive devices: Numerous devices have been developed to potentially improve the effectiveness of CPR. Mechanical compression devices that administer automated chest compressions (using battery or compressed-gas power) are now offered by several manufacturers, and have generally been shown to be equally effective to high-quality manual compressions, although not superior. An “impedence threshold device” or ITD is offered by one manufacturer (as the ResQPod), which creates negative pressure inside the thorax to improve cardiac preload; early research was ambiguous as to its effectiveness, but more recent studies have suggested it may have benefit when combined with active compression-decompression CPR (ACD-CPR, which uses plunger-like devices to allow for both compression and active “pulling” during recoil). Monitors or AEDs that provide real-time audiovisual feedback during CPR, ensuring that rescuers provide compressions at the desired rate and depth, are increasingly common and may improve CPR quality.
Post-arrest care and therapeutic hypothermia: Post-arrest hypothermia, where a patient is cooled after ROSC is obtained (generally only if they remain comatose), has been definitively shown to improve survival to discharge with good neurological status. Most of this research is for shockable rhythms; evidence for its use after asystole or PEA is minimal, although most clinicians presume its effectiveness. Details such as target temperature, time-at-temperature, when to induce (prehospital cooling has become increasingly common, in some cases initiated intra-arrest, but has not been shown to improve outcomes over later induction in the ED), and other matters have not yet been established in large trials. Manner of cooling has generally been shown to be immaterial; chilled saline, external ice packs, and external cooling blankets are currently the most common approaches, although invasive techniques (such as peritoneal lavage) are also available. Other post- or peri-arrest therapies, such as early PCI for patients with STEMI (perhaps even prior to ROSC), emergency ECMO, “ischemic preconditioning,” and more are currently being studied.
Prevalence, prognosis, and community health: Due to the importance of bystander intervention in recognizing SCA, activating EMS, and providing early CPR and defibrillation, as well as the importance of rapid EMS response, ample research has been done into: risk factors for arrest; prognosis for arrest at various times and settings; impact on survival of common EMS models and response times; impact of bystander compressions, AED use, dispatch-delivered telephone instructions for CPR, and other measures; and optimal strategies for improving bystander willingness and ability to intervene for SCA patients.
Editor’s note: this shelf is still in the early stages of development. A substantial amount of important material still remains to be added before the state of the literature is effectively represented.
To view newly added material, search for the triple asterisk (***)
[1-14-14] 3 papers added.
[5-13-13] 6 papers added.
[4-18-13] Shelf created. 9 papers added.
|Chest Compression-Only CPR by Lay Rescuers and Survival From Out-of-Hospital Cardiac Arrest||Bobrow BJ, Spaite DW, Berg RA, Stolz U, Sanders AB, Kern KB, Vadeboncoeur TF, Clark LL, Gallagher JV, Stapczynski JS, LoVecchio F, Mullins TJ, Humble WO, Ewy GA||2010||Prospective cohort study, multi-site||4415||Outcomes of OOHCA were compared using multi-variate logistical regression between patients who received no bystander CPR, CPR with ventilations, and compression-only CPR.||Compression-only CPR was associated with improved mortality compared to conventional CPR when performed by lay rescuers.||4|
|Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest||Stiell IG, Wells GA, Field B, Spaite DW, Nesbitt LP, De Maio VJ, Nichol G, Cousineau D, Blackburn J, Munkley D, Luinstra-Toohey L, Campeau T, Dagnone E, Lyver M; Ontario Prehospital Advanced Life Support Study Group.||2004||Prospective, non-randomised controlled trial.||5638||OPALS trial: 1391 OCHA patients enrolled before introduction of ACLS capable EMS, 4247 enrolled subsequent to ACLS up skilling. Mortality rates compared between groups.||The addition of advanced-life-support interventions did not improve the rate of survival after out-of-hospital cardiac arrest in a previously optimized EMS system of rapid defibrillation.||5|
|Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial.||Jacobs IG, Finn JC, Jelinek GA, Oxer HF, Thompson PL.||2011||Prospective, double blind, randomised controlled trial, single-site||534||PACA trial: Enrolled adult SCA patients in Western Australia, any etiology, who were unresponsive to three shocks or had a non-shockable initial rhythm. Patients received 1ml IV boluses (max 10ml) of either 1:1000 epinephrine or normal saline drawn from sealed, unlabeled vials. No other drugs given. Outcomes were compared.||Patients receiving epinephrine had increased likelihood of ROSC (OR 3.4); increased survival to hospital admission (OR 2.3); and insignificantly increased survival to discharge (OR .7-6.3). Most survivors had good neuro outcome. The effect of epi on ROSC was greater in non-shockable rhythms. The study was underpowered due to some services opting out. (Cohort details: 48% witnessed; 51% bystander CPR; 46% shockable initial rhythms)||5|
|Cardiac resuscitation in the community. Importance of rapid provision and implications for program planning.||Eisenberg MS, Bergner L, Hallstrom A.||1979||Retrospective analysis, single-site.||569||Data mine from cardiac arrest registry enrolling all patients from the King County, WA area. Studied witnessed out-of-hospital cardiac arrests and compared outcomes with duration of EMS response.||Time-to-CPR 4 mins had 12%. Time-to-defib/ALS 8 mins had 13%. With both intervals >8 mins, only 3% survived.||4|
|Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest.||Bobrow BJ, Clark LL, Ewy GA, Chikani V, Sanders AB, Berg RA, Richman PB, Kern KB.||2008||Prospective trial, retrospective control, interrupted time series, multi-site||486||Before-and-after study of adult, presumed-cardiac-etiology sudden cardiac arrests in two large Arizona cities. Taught responders to use 100 continuous compressions, one shock if indicated, and 100 more compressions before utilizing other interventions. Outcomes compared.||Survival to discharge increased from 1.8% before CCR-style training to 5.4% after (OR 3.0). Witnessed arrests with shockable rhythms had survival from 4.7% to 17.6% (OR 8.6). 61.1% of patients were treated in compliance with the new technique, and OR for their survival was 2.7-3.4, with similar neuro outcomes.||3|
|Hypothermia for neuroprotection in adults after cardiopulmonary resuscitation.||Arrich J, Holzer M, Havel C, M√ºllner M, Herkner H.||2012||Systematic review with partial meta-analysis||5||Cochrane Review of 5 RCTs (total 481 patients) investigating survival and neurological outcome when therapeutic hypothermia was used for adult patients after cardiac arrest, any method, applied within six hours.||Patients treated with hypothermia were more likely to survive to hospital discharge (RR 1.35) and more likely to have good neurological recovery in-hospital (RR 1.55). There was no increase in adverse events.||5|
|Naloxone in cardiac arrest with suspected opioid overdoses.||Saybolt MD, Alter SM, Dos Santos F, Calello DP, Rynn KO, Nelson DA, Merlin MA.||2010||Retrospective cohort study, single-site||36||Chart review; enrolled patients who received naloxone during cardiac arrest (via medical control authorization) in a large ALS system, and investigated their outcomes.||42% of cardiac arrests receiving naloxone experienced a rhythm change, half of them immediately. 20% of these experienced ROSC, and 7% (1 person, positive for opiates) survived to discharge, versus 0% of non-responders.||3|
|Quality of cardiopulmonary resuscitation in out-of-hospital cardiac arrest is hampered by interruptions in chest compressions--a nationwide prospective feasibility study.||Krarup NH, Terkelsen CJ, Johnsen SP, Clemmensen P, Olivecrona GK, Hansen TM, Trautner S, Lassen JF.||2011||Prospective cohort study, single-site||191||Enrolled all adult out-of-hospital sudden cardiac arrests (non-traumatic) over one month in Denmark. Analyzed arrests using registry data and downloaded cardiac monitor data.||Chest compression fraction was ~.5 overall. Compression rates were >130/min, yet were halted in excess of 20 seconds before and after defibrillation, and over 220 seconds while loading onto the ambulance. (Cohort details: 52% witnessed; 39% bystander CPR; 23% shockable initial rhythm; 4.7% one-year survival)||2|
|Prehospital epinephrine use and survival among patients with out-of-hospital cardiac arrest.||Hagihara A, Hasegawa M, Abe T, Nagata T, Wakata Y, Miyazaki S.||2012||Prospective, non-randomized propensity analysis||417188||Data mine of national registry; enrolled all adult out-of-hospital sudden cardiac arrests (not witnessed by EMS) over four years in Japan. Compared outcome between those who received epinephrine from EMS vs. those who did not, after matching for other variables.||Patients receiving epinephrine had greater likelihood of ROSC (OR 2.51) but lower 1-month survival (OR .54) and worse neurological outcomes (OR ~.22). (Cohort details: 21% witnessed; 36% bystander compressions; 7.4% shockable initial rhythm)||4|
|Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest.||Olasveengen TM, Sunde K, Brunborg C, Thowsen J, Steen PA, Wik L.||2009||Prospective, double blind, randomised controlled trial, single-site||851||Enrolled adult, non-traumatic SCA patients treated by an ALS (physician-assisted) system in Norway. Patients were randomized on scene to receive either standard ACLS care or ACLS without any IV access or medications (prior to ROSC). Outcomes compared.||1.3% more patients in the IV group survived to discharge (OR 1.16, insignificant). 1.7% more of the IV group had good neuro outcome (OR 1.24, insignificant). The IV group had significantly greater ROSC (OR 1.99), survival to admission (OR 1.81), and survival to ICU admission (1.67). All early benefit was in non-shockable rhythms, but this was eliminated by higher in-hospital mortality, mostly from brain damage. After adjusting for confounders, the IV group had significantly better survival to ICU admission and discharge, and in shockable rhythms had far better survival to discharge (AOR 10.47); the benefit was closely linked to downtime. (Cohort details: 65% witnessed; 63% bystander CPR; 33% shockable initial rhythms; EMS compression fraction .85; ~71% received post-ROSC hypothermia.)||4|
|Effects of compression depth and pre-shock pauses predict defibrillation failure during cardiac arrest.||Edelson DP, Abella BS, Kramer-Johansen J, Wik L, Myklebust H, Barry AM, Merchant RM, Hoek TL, Steen PA, Becker LB.||2006||Prospective cohort study, multi-site||60||Enrolled consecutive adult SCA patients from one in-patient and one out-of-hospital setting (excluding ED and OR patients), if their initial rhythm was VF. Used a compression feedback device to measure compression quality during the 30 seconds prior to defibrillation (pre-shock pause). Outcomes compared.||Successful defib shocks (rhythm conversion) tended to follow briefer pre-shock pauses (11.9s vs 22.7s) and deeper compressions (39mm vs 29mm). Adjusting for confounders and regressing a curve, each 5s decrease in pre-shock pause was associated with 86% better shock success, and each 5mm increase in depth with 99% better success. Effect on survival was insignificant. Ventilatory rate, compression rate, and no-flow time were all similar. (Cohort details: 55% out-of-hospital arrests; 3.7 min time-to-first-shock; 53% ROSC; 7% survival to discharge)||2|
|Low chance of survival among patients requiring adrenaline (epinephrine) or intubation after out-of-hospital cardiac arrest in Sweden.||Holmberg M, Holmberg S, Herlitz J.||2002||Retrospective cohort study, multi-site||10966||Data mine of Swedish cardiac arrest registry. Enrolled all out-of-hospital SCA patients where resuscitation was attempted; compared outcomes between patients who received epinephrine and intubation versus patients who received neither.||About half of patients received epinephrine and a similar number received intubation. After regression, epi (OR .43) and intubation (OR .71) both reduced 1-month survival. Neither intervention improved survival in any subgroup; most subgroups yielded insignificantly worse survival. (Cohort details: 70.1% witnessed; ~32% bystander CPR; 43.3% shockable initial rhythm)||3|
|Rapid Epinephrine Administration Improves Early Outcomes in Out-of-Hospital Cardiac Arrest.||Koscik C, Pinawin A, McGovern H, Allen D, Media D, Ferguson T, Hopkins W, Sawyer K, Boura J, Swor R.||2013||Retrospective cohort study, single-site||686||Chart review. Enrolled adult, non-traumatic SCA patients who received epinephrine, from a registry of three suburban communities, 2005-2011. Evaluated duration until administration of epinephrine, and compared against outcome.||In a multi-variate model, receiving epi within 10 minutes of 911 call vs >10mins improved ROSC (OR 1.78) but not survival to discharge (OR .91). The effect was greater in witnessed arrests (OR 3.20 to ROSC and 1.48 to survival), less in PEA, and negligible in asystole. (Cohort details: 47% witnessed; 20% bystander CPR; 911-to-EMS-arrival time: ~4.7min; 25% shockable initial rhythm)||3|
|Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest.||Kellum MJ, Kennedy KW, Barney R, Keilhauer FA, Bellino M, Zuercher M, Ewy GA.||2008||Prospective trial, retrospective control, interrupted time series, multi-site||181||Before-and-after study of adult, witnessed, presumed-cardiac-etiology SCA patients in two Wisconsin counties; retrospectively gathered data on outcomes 2001-2003 (all resuscitation according to 2000 AHA guidelines) and compared it to prospective data from 2004-2007 (CCR-type resuscitation instituted). Therapeutic hypothermia was an exclusion.||20% of patients survived in the initial cohort vs. 47% in the CCR cohort. 15% of the initial cohort's survivors were neurologically intact vs. 39% of the CCR cohort. Variables of both cohorts were generally similar. (Cohort details: ~45% bystander CPR; ~8min response times)||2|
|Survival outcomes with the introduction of intravenous epinephrine in the management of out-of-hospital cardiac arrest.||Ong ME, Tan EH, Ng FS, Panchalingham A, Lim SH, Manning PG, Ong VY, Lim SH, Yap S, Tham LP, Ng KS, Venkataraman A; Cardiac Arrest and Resuscitation Epidemiology (CARE) Study Group.||2007||Prospective trial, retrospective control, interrupted time series, multi-site||1296||Before-and-after study of adult, non-traumatic SCA patients treated by Singapore ambulances (EMT-Intermediate equivalents; AED, no intubation). Use of IV access and 1 dose of 1mg epinephrine were introduced into their BLS resuscitation algorithm; outcomes are compared from before and after the change.||Epinephrine was associated with a negligible effect on ROSC (OR .9) and survival to admission (OR 1.0). It insignificantly improved survival to discharge (OR 1.7). The effect was greater in VF/VT (OR 2.0); in PEA/asystole there was insignificant harm or no effect at all intervals. Other subgroup analysis had little effect. (Cohort details: 67% witnessed; 19% bystander CPR; 20% initial shockable rhythm; 911-to-patient-side: 11.5min)||3|
|Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest.||Wik L, Kramer-Johansen J, Myklebust H, S√∏reb√∏ H, Svensson L, Fellows B, Steen PA.||2005||Prospective observational study, multi-site||176||Enrolled adult SCA patients in three European cities, no exclusions. Ambulances were equipped with defibrillators that recorded compressions using an accelerometer; the quality of CPR was compared against 2000 ILCOR guidelines.||Avg. compression fraction (CF) was ~.51, or ~.6 when protocol-approved pauses were subtracted (for rhythm analysis, defibrillation, etc); CF dropped slightly after the first 5 minutes. Compression rate was ~120/min and depth was ~35mm (1.4in). Only ~27% of compressions were within the recommended depth, and ~60% were too shallow. Compressing too deep or without full recoil was rare. Ventilations were 8-11/min. 35% of all patients had ROSC, 19% were admitted, and 3% discharged alive. Survival was insignificantly better among patients with higher CF and slower ventilations.||3|
|Excessive chest compression rate is associated with insufficient compression depth in prehospital cardiac arrest.||Monsieurs KG, De Regge M, Vansteelandt K, De Smet J, Annaert E, Lemoyne S, Kalmar AF, Calle PA.||2012||Prospective observational study, single-site||133||Enrolled consecutive adult SCA patients from a town in Belgium (2005 ERC guidelines). A Zoll monitor with compression feedback was used (with real-time prompting if compressions were too shallow or slow, but not too deep or fast); the recorded accelerometer data was later analyzed to determine any relationship between rate and depth of compressions.||30% of all compressions were within 2005 ERC guidelines for rate/depth; a third were over 120/min. When rate >120/min, most compressions were shallower than when rate 80-120, and for a third were more than .5cm shallower. When regressed, depth tends to increase with rate until 86/min, then begins to gradually decrease with higher rates, particularly beyond 145/min.||3|
|Survival models for out-of-hospital cardiopulmonary resuscitation from the perspectives of the bystander, the first responder, and the paramedic.||Waalewijn RA, de Vos R, Tijssen JG, Koster RW.||2001||Prospective observational study, single-site||1030||Enrolled consecutive, non-traumatic, witnessed adult SCA patients in Amsterdam. Research personnel responded with EMS and recorded time intervals, which were correlated against outcomes.||After multivariate analysis, survival decreased by 26% per minute without bystander CPR, but only 13% with CPR. For shockable rhythms, each minute between CPR and defibrillation decreased survival by 17%, and each minute between CPR and advanced (ALS-level) CPR by 11%, although many of the survivors had ROSC before ALS arrival.||3|
|Estimating effectiveness of cardiac arrest interventions: a logistic regression survival model.||Valenzuela TD, Roe DJ, Cretin S, Spaite DW, Larsen MP.||1997||Retrospective analysis, multi-site||1872||Enrolled adult, presumed-cardiac-etiology, witnessed SCA patients with a shockable initial rhythm from two US cities. Calculated or estimated intervals to various interventions and regressed their effect on outcome.||With logistic regression, survival to discharge could be adequately modeled using only two variables, collapse-time-to-CPR and collapse-time-to-defibrillation. Each minute until CPR decreased survival by 10.6%; each minute until defib decreased survival by 13.9%.||4|
|Quantifying the effect of cardiopulmonary resuscitation quality on cardiac arrest outcome: a systematic review and meta-analysis.||Wallace SK, Abella BS, Becker LB.||2013||Systematic review with meta-analysis||4722||Meta-analysis of 10 studies of cardiac arrest looking at the association between mortality and the rate and depth of compressions, ventilation rate, and compression fraction.||Arrest survivors were significantly more likely to have
chest compressions than nonsurvivors (mean difference, 2.44 mm) and more likely to have received chest compression rates closer to 85 to 100 compressions per minute (cpm) than nonsurvivors. No associations were found in terms of compression fraction or ventilation rate.
|Cardiac arrest survival is rare without prehospital return of spontaneous circulation.||Wampler DA, Collett L, Manifold CA, Velasquez C, McMullan JT.||2012||Retrospective analysis, multi-site||2483||Registry analysis from two large urban US systems; enrolled all OHCA of presumed cardiac etiology. Analyzed effect on survival of achieving ROSC prior to transport versus transporting without pulses.||Survival to discharge occurred in 17.2% of patients with ROSC on scene, and in .69% of patients without. Of the non-field-ROSC survivors, 72% had witnessed arrests (18% EMS-witnessed), 72% had an initially shockable rhythm, and none were asystolic. (Cohort details: 52% witnessed; ~40% bystander CPR; ~20% shockable initial rhythm)||3|
|Effectiveness of bystander cardiopulmonary resuscitation and survival following out-of-hospital cardiac arrest.||Gallagher EJ, Lombardi G, Gennis P.||1995||Prospective cohort study, single-site||2071||Enrolled witnessed, presumed-cardiac-etiology OHCA in New York City. First responders recorded the presence of bystander CPR, and its effectiveness according to 1) visible chest rise with ventilation, and 2) palpable carotid or femoral pulses with compressions (a pilot group validated this method). The effect on survival to discharge with good neurological status was analyzed.||32% of patients had bystander CPR; 46% of those were considered effective. Survival without CPR: .8%. With CPR: 2.9% (OR 3.7). With ineffective CPR: 1.4%. With effective CPR: 5.8% (OR 3.4 vs ineffective, 5.7 vs none). Among ineffective CPR, 29% had good compressions and bad ventilation (survival 2.0%), and 7% had good ventilations and bad compressions (0%) survival; in 64% both were bad, for .6% survival.||4|
|Wide variability in drug use in out-of-hospital cardiac arrest: a report from the resuscitation outcomes consortium.||Glover BM, Brown SP, Morrison L, Davis D, Kudenchuk PJ, Van Ottingham L, Vaillancourt C, Cheskes S, Atkins DL, Dorian P; Resuscitation Outcomes Consortium Investigators.||2012||Retrospective analysis, multi-site||16221||ROC registry analysis (264 agencies, 11 sites); enrolled adult SCA patients treated by ALS between 2005-2007. The usage of intra-arrest drugs was analyzed for prevalence between services, and for correlation with survival to discharge after statistically controlling for variables.||Amiodarone was used ~.4-90% of arrests depending on service, and lidocaine in ~1-100%; OR for refractory VF/VT was 1.11 and 1.28 respectively (insig). Epinephrine was used in 57-98% of patients, mean dose 1.9-5.5mg; there was an inverse relationship between dose and survival. Atropine was used in 29-95% of cases; it had an inverse relationship with survival (OR .11). Bicarbonate was used in .3-71% of cases, mostly irrespective of arrest duration; it had an inverse relationship with survival (OR .13).||5|
|Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation.||Kudenchuk PJ, Cobb LA, Copass MK, Cummins RO, Doherty AM, Fahrenbruch CE, Hallstrom AP, Murray WA, Olsufka M, Walsh T.||1999||Prospective, double blind, randomised controlled trial, single-site||504||Enrolled adult, non-traumatic SCA patients in Seattle/King County (1994-1997) who had with VF/VT persisting despite 3 shocks. Patients were intubated, received 1mg epinephrine, then (from an unlabeled vial) either 300mg amiodarone IV or a placebo. Outcomes compared.||On average, amiodarone/placebo was administered after five shocks. After controlling for variables, those receiving amio were more likely to survive to admission (OR 1.6); the effect persisted for any time-to-treatment, and was greater in women (OR 4.3 vs OR 1.2 in men). Survival to discharge and neuro status, however, were similar in both groups.||3|
|An evidence-based evaluation of the use of sodium bicarbonate during cardiopulmonary resuscitation.||Levy MM.||1998||Systematic review||59||Reviews all available literature on the safety and benefit of administering IV bicarbonate during cardiac arrest.||One RCT has shown no benefit of bicarb on SCA survival; several studies have shown deleterious effects on surrogate markers; several animal trials have shown deleterious effects on survival (although never in v-fib), some have shown survival benefit, and others no effect. No study has shown a benefit on human survival.||2|
|Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos.||Valenzuela TD, Roe DJ, Nichol G, Clark LL, Spaite DW, Hardman RG.||2000||Prospective observational study, multi-site||148||Enrolled security staff from 32 casinos, who received standardized BLS training. Staff agreed to observe customers in public areas of the facility via security camera, and in case of sudden collapse immediately respond with public-access AEDs. All adult SCA patients were analyzed for outcomes.||Of all arrests: 11% pronounced dead on scene, 41% died in ED, 10% died as inpatients, 38% survived to discharge. Of witnessed VF: 2% pronounced dead on scene, 29% died in ED, 10% died as inpatients, 59% survived to discharge. Survival for witnessed arrests was 74% if shocked within 3 minutes and 49% otherwise. (Cohort details: 80% male, mean age 64; ~49% pre-defib CPR; ~2.9min collapse-to-CPR; 71% initially shockable rhythm; ~4.4min collapse-to-shock; ~9.8min collapse-to-ALS)||3|
|Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial.||Aufderheide TP, Frascone RJ, Wayne MA, Mahoney BD, Swor RA, Domeier RM, Olinger ML, Holcomb RG, Tupper DE, Yannopoulos D, Lurie KG.||2011||Prospective pseudo-randomized, controlled trial, multi-site||1653||EMS services in seven US regions (2005-2009) enrolled adult SCA patients with presumed cardiac etiology who had received >1 minute of CPR. Patients calendar-randomized to receive either standard CPR or ACD-CPR using the ResQPump/CardioPump device (which includes metronome and depth feedback) at 80/min, plus the ResQPod impedence threshold device (ITD) on facemask or ET tube. Both arms retrained in high-quality CPR. Non-rescuer researchers blinded. Outcomes compared. [Sponsored by device manufacturer.]||Survival to discharge with good neuro outcome (modified Rankin <4) was 8.9% in study group vs 5.8% in control (relative increase 53%, OR 1.58, significant). The effect persisted to 1 year, but was weaker in shockable rhythms. Neuro outcomes and adverse effects were similar in both groups, but pulmonary edema was slightly greater in study arm. Study ended early due to funding. (Cohort details: 56% witnessed; 43% bystander CPR; 32% shockable initial rhythm; 6.6min 911-to-EMS; 85%+ hypothermia; 72%+ PCI)||4|
|Assessment of CPR interruptions from transthoracic impedance during use of the LUCAS mechanical chest compression system||Yost D, Phillips RH, Gonzales L, Lick CJ, Satterlee P, Levy M, Barger J, Dodson P, Poggi S, Wojcik K, Niskanen RA, Chapman FW.||2012||Retrospective analysis of chart data and surveys, multi-site||32||Using data from three participating sites in the North American LUCAS Evaluation project from November 2008 to February 2010, a retrospective review of provider usage surveys and physiologic data from the cardiac monitor was performed. 327 patients were identified, of which 32 cases had complete data. Surveys were completed with each call which asked the providers about the ease of usage and duration to deploy the device. Impedance and ECG data was collected from the defibrillators and used to determine chest compression parameters, which served as the benchmark for each case. Case data was analyzed and compared to the survey for this study.||Median time to deploy the LUCAS 1 device was 32.5 seconds (IQR 25-61). Providers were unable to accurately determine how long it took them to deploy the device. Pauses in chest compressions were often twice as long as the provider's perceived them to be. However, compression rate and compression fraction remained within guidelines (104/min and 0.88 respectively).||2|
|High dose versus standard dose epinephrine in cardiac arrest - a meta-analysis.||Vandycke C, Martens P.||2000||Meta-analysis||6339||Systematic review on high-dose epinephrine. Included prospective, double-blinded RCTs of adult SCA patients published in journals with "high impact factor," all comparing high- or escalating-dose epi vs normal dose epi. Pooled data on mortality to generate odds ratios.||Five RCTs were found between 1989-1996. Most showed statistically insignificant improvements in ROSC from high-dose epi (one was significant), but the pooled OR for ROSC was 1.14 and significant. There was no significant effect on survival to admission, and there was a significant negative effect on survival to discharge (OR .74).||4|
|Tissue Plasminogen Activator in Cardiac Arrest with Pulseless Electrical Activity.||Abu-Laban RB, Christenson JM, Innes GD, van Beek CA, Wanger KP, McKnight RD, MacPhail IA, Puskaric J, Sadowski RP, Singer J, Schechter MT, Wood VM.||2002||Prospective, double blind, randomised controlled trial, multi-site||233||Either paramedics or ED staff enrolled adult SCA patients with over 1 minute of PEA (no obvious non-cardiac etiology) who were unresponsive to initial care. Patients randomized to receive 100 mg tPA or placebo (IV over 15 minutes) from unlabeled vials, with resuscitation continued at least 15 minutes afterward. Outcomes compared.||25 tPA patients had ROSC vs 27 placebo. 7 tPA patients survived to admission vs 6 placebo. 1 tPA patient survived to discharge vs. no placebo patients. Median time from collapse to tPA was 35mins. 21.4% of patients had AMI on autopsy and 2.4% had PE. (Cohort details: 65% witnessed; ~46% bystander CPR; ~62% initial PEA, 22% asystole, 24% VF; 100% intubated and received 1mg epi)||3|
|Thrombolysis during resuscitation for out-of-hospital cardiac arrest.||Bottiger BW, Arntz HR, Chamberlain DA, Bluhmki E, Belmans A, Danays T, Carli PA, Adgey JA, Bode C, Wenzel V; TROICA Trial Investigators; European Resuscitation Council Study Group.||2008||Prospective, double blind, randomised controlled trial, multi-site||1050||In 2004-2006, 66 EMS services across Europe enrolled witnessed adult SCA patients of presumed cardiac etiology and CPR administered within 10 minutes of collapse. Those with initial PEA or asystolic rhythm, or VF/VT patients refractory to 3 defibrillations, were cluster-randomized to receive 30-50mg IV tenecteplase or placebo. Resuscitation continued 30+ minutes after, and heparin/aspirin/GPIIbIIIa use were discouraged. (Industry-sponsored and designed trial.)||Trial stopped early due to lack of benefit. There was no significant difference in ROSC, survival to admission or discharge, neuro outcome, or 30-day survival. Intracranial hemorrhage occurred 2.7% (signif.) more often with lytics. Excluding asystole patients or other subgroup analysis had no effect. (Cohort details: ~2 mins collapse-to-CPR; ~12 mins collapse-to-defib; 18 mins collapse-to-lytics; 71% presumed AMI; 9% presumed PE; ~16% survival to discharge)||3|
|*** Patients with cardiac arrest are ventilated two times faster than guidelines recommend: An observational prehospital study using tracheal pressure measurement.||Maertens VL, De Smedt LE, Lemoyne S, Huybrechts SA, Wouters K, Kalmar AF, Monsieurs KG.||2012||Prospective observational study.||98||98 patients (57 with and 41 without cardiac arrest) had an air-filled catheter placed into their endotracheal tube which was connected to a device which measured air pressures to record ventilatory rates during resuscitation. This technology is also being used in a study of devices to detect esophageal intubation. (Study was supported by an Industrial Research Fund grant from Ghent University which has filed a patent regarding the technology used)||Ventilation rates for patients in cardiac arrest, delivered either manually or with a ventilator, were almost uniformly higher than the recommended 10/min rate. For manually ventilated patients in cardiac arrest the median rate was 20/min (min: 4/min, max: 74/min, IQR: 13-31) with 90% (n=43) greater than 10/min. For mechanically ventilated patients in cardiac arrest the median rate was 15/min (min: 8/min, max: 44/min; IQR: 12-20) with 92% (n=38) greater than 10/min. Interestingly, the median ventilation rates for both manual and mechanical means were lower in patients without cardiac arrest.||4|
|*** Effects of prehospital epinephrine during out-of-hospital cardiac arrest with initial non-shockable rhythm: an observational cohort study.||Goto Y, Maeda T, Goto YN.||2013||Prospective cohort study, multi-site||209577||Registry analysis of Japanese adult cardiac arrests over 1 year. Compared outcomes between arrests (shockable and non-shockable) who received epinephrine versus those who did not, and evaluated the effect of time-to-epinephrine administration.||For shockable rhythms, the non-epinephrine group had significantly better ROSC (28% vs 23%), 1-month survival (27% vs 15%), and 1-month neuro status (19% vs 7%). For non-shockable rhythms, the epi group had better ROSC (19% vs 3%) and 1-mo survival (4% vs 2%), with no difference in neuro-intact survival. The subgroup of epi administration <20mins had better 1-mo survival (OR 1.78) but worse 1-mo neuro status (OR .63).||4|
|*** Vasopressin, steroids, and epinephrine and neurologically favorable survival after in-hospital cardiac arrest: a randomized clinical trial.||Mentzelopoulos SD, Malachias S, Chamos C, Konstantopoulos D, Ntaidou T, Papastylianou A, Kolliantzaki I, Theodoridi M, Ischaki H, Makris D, Zakynthinos E, Zintzaras E, Sourlas S, Aloizos S, Zakynthinos SG.||2013||Prospective, double-blind, randomized controlled trial, multi-site||268||Consecutive cardiac arrest patients among adult inpatients in three Greek tertiary hospitals received either vasopressin and steroids (methylprednisolone and hydrocortisone) or placebo. Both arms received epinephrine. Outcomes and lab measures were compared.||Patients in the treatment arm had more ROSC (84% vs 66%, OR 2.98) and neuro-intact survival to discharge (14% vs 5%, OR 3.28). They also had reduced complications and improved laboratory markers.||4|